CHICAGO —  The mother of a pregnant postal worker who disappeared more than four years ago made a new plea for help on Tuesday.

Activists raised the reward money to $68,000 for information on the whereabouts of Kierra Coles, who was last seen on Oct. 2, 2018 near 83rd and King Drive. Coles’ car was found parked on her block with her purse and cell phone still inside.

Coles was three months pregnant at the time of her disappearance.

SEE ALSO | Chicago police have released video of the last known images of Kierra Coles

Karen Phillips, Coles’ mother, hopes the FBI will become involved in the search for her missing daughter.

“Can’t nobody image the pain that I go through daily,” Phillips said. “Missing my child, not hearing her voice. Not knowing if she had her child. Not knowing if she is suffering every day. No knowing if her child is suffering every day. Please help me bring Kierra home. And to Kierra, if you are watching this. We’re not going to stop. I’m trying to do everything in my power to help bring you home.”

Last June, Chicago police released surveillance video showing Coles walking into her apartment in the 8100 block of S. Vernon and then leaving and entering a car with a male hours later.

Coles later withdrew money from an ATM inside a store in the 8600 block of S. Cottage Grove. She exits minutes later in what police said are the last recorded images of the 26-year-old.

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Anyone with information may submit an anonymous tip to police at cpdtip.com.

Chicago police suspect foul play and say her case remains classified as a high-risk missing persons investigation.